Oil stain on the aluminium foil sheet surface refers to the phenomenon of excessive oil on the surface of finished aluminum tapes. The oil can be observed by the naked eye during slitting and finished product inspection, and usually contains extra alien oil different from rolling oil film. The oil stain has a serious negative effect on the surface of aluminum foil. Most finished aluminum foils will be further processed into decorative or packing products, which have high requirement about cleanness of the surface. Besides, foils with oil stains prove to be thinner than quality foils, and they are likely to become bubbles in the following annealing process. Excessive oil remains also lead to negative affect in usage of the aluminium foil sheet.

Then how to reduce the oil stains? The stains are mainly from the following sources. First, oil from the roller neck or outlet might drop on the foil. Second, oil stains will be left on he foil surface from the roller side when there is something wrong with rolling cleaners. The stains are usually of complicated constituents and extremely difficult to be eliminated. Therefore, to solve the problem operators should clean regularly the roller neck and check the operating state of the rolling cleaner. Oil stain defect remains to be a crucial index in estimating the quality of aluminium foil sheets, and it’s worth manufacturers paying special attention to the problem.